E.g. I have buttonbar button with Russian hint. If I have EN keyboard layout active when copying button via context menu, TC copies button code in wrong encoding (even when I paste text into Unicode application, text is wrong), but if I switch to RU all is right.

This is a known Windows bug: When you call SetClipboardData(CF_TEXT,..) and do not explicitly set the encoding, Windows seems to use the current keyboard layout for the encoding. Since TC ignores the encoding setting of the clipboard when you paste a button, this doesn't matter for copying/pasing buttons, it only matters when you want to paste the button details somewhere else.

I even have a fix for this bug in TC: Call SetClipBoarddata(CF_LOCALE,...). I just didn't use it in this function because it wasn't meant to copy button data anywhere else..._________________Author of Total Commander
http://www.ghisler.com

I don't understand. When you're copying text to clipboard, you can copy it in any encoding (just specify right one for clipboard format), and when you're pasting text from clipboard, you can choose in which encoding you want to see it, so it won't be a problem if you copy Unicode text in TC 7.55 and then try to paste it in local ANSI codepage in TC 7.04a e.g. - Windows will convert text for you (you just need to specify encoding).